A woman has been arrested after a mother and her two children were struck by a car in Markham Friday morning.

York Regional Police said a vehicle crashed in the area of Kennedy Road and Clayton Drive, shortly before 10 a.m., after the driver somehow lost control. 

Police say a vehicle was travelling northeast on Harvest Moon Drive when it lost control, striking the three pedestrians. For unknown reasons, police say the vehicle continued on, striking another car, then continuing east on Clayton Drive before colliding into the side of a church. 

Police said a mother, 37, and her two sons were injured in the crash, which occurred near the Milliken Wesleyan Methodist Church.

Police said one of the children is six years old, while the other is younger.

The younger child was rushed to a nearby hospital with life-threatening injuries, which have since been upgraded, police said.

Investigators said it appeared that the children may have been crossing the street at the time of the crash, but details are unclear.

Police said witnesses told them the woman and children had gotten off the bus right before they were struck. 

One witness said the driver told her she'd been trying to drive around the bus, but there seemed to be a problem with her brakes.

Witnesses said the 67-year-old female driver who crashed into the church appeared to be unharmed. She was arrested at the scene for dangerous driving. 

Clayton Drive is closed between Kennedy Road and Harvest Moon Drive for the police investigation.

Anyone with more information is asked to call the York Regional Police Major Collision Investigations Unit at 1-866-876-5423, ext. 7704.

With a report from CTV Toronto's Tamara Cherry 

Car crash in Markham